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Vuerich M, Harshe R, Frank LA, Mukherjee S, Gromova B, Csizmadia E, Nasser IAM, Ma Y, Bonder A, Patwardhan V, Robson SC, Longhi MS. Altered aryl-hydrocarbon-receptor signalling affects regulatory and effector cell immunity in autoimmune hepatitis. J Hepatol 2021; 74:48-57. [PMID: 32663496 PMCID: PMC7749856 DOI: 10.1016/j.jhep.2020.06.044] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 06/15/2020] [Accepted: 06/24/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS In autoimmune hepatitis (AIH), the imbalance between regulatory T cells (Tregs) and T-helper type 17 (Th17) cells has been linked to low levels of CD39, an ectoenzyme that hydrolyses ATP, ultimately generating immunosuppressive adenosine. Upregulation of CD39 results from activation of aryl hydrocarbon receptor (AHR), which mediates toxin responses to modulate T-cell immunity. In this study, we investigated whether altered AHR signalling underlies defective CD39 expression and function in AIH Tregs and Th17 cells, therefore contributing to regulatory/effector cell imbalance. METHODS Tregs and Th17 cells, obtained from the peripheral blood of 49 patients with AIH and 21 healthy individuals (HI), were tested for response to endogenous and exogenous AHR ligands. RESULTS When compared to those of HI, AIH-derived Tregs and Th17 cells displayed impaired responses to AHR activation, reflected by impaired upregulation of CD39, delayed increase in ectoenzymatic activity, and defective Treg suppressive function. These impairments resulted, at least in part, from heightened levels of AHRR and Erα in Tregs and high HIF-1α in Th17 cells, and were reverted upon molecular blockade. Importantly, in AIH-derived Tregs, the binding affinity of AHR was higher for Erα than ARNT. CONCLUSIONS In AIH, high levels of AHRR and HIF-1α inhibit AHR signalling in Tregs and Th17 cells. AHR non-canonical binding to Erα further amplifies the lack of effective CD39 upregulation. Blockade of these inhibitory and/or non-canonical activation pathways represents a potential therapeutic approach to restore CD39 and immunohomeostasis in AIH. LAY SUMMARY In patients with autoimmune hepatitis, the imbalance between regulatory T cells and T helper type-17 cells is linked to dysfunction of the aryl hydrocarbon receptor pathway, resulting from aberrant inhibition or non-canonical activation. These alterations impair Treg- and Th17 cell-induced upregulation of CD39, an ectoenzyme key to immunoregulation. Blockade of excessive inhibition or non-canonical activation of the aryl hydrocarbon receptor pathway might represent a novel therapeutic strategy to control inflammation while restoring immune balance in autoimmune hepatitis.
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Affiliation(s)
- Marta Vuerich
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Rasika Harshe
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Luiza Abrahão Frank
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Samiran Mukherjee
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Barbora Gromova
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA,Institute of Molecular Biomedicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Eva Csizmadia
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Imad AM Nasser
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Yun Ma
- Institute of Liver Studies, Department of Inflammation Biology, School of Immunology & Microbial Sciences, Faculty of Liver Sciences and Medicine, King’s College London, London, United Kingdom
| | - Alan Bonder
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Vilas Patwardhan
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Simon C. Robson
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA,Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Maria Serena Longhi
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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Burnstock G. Purinergic Signalling: Therapeutic Developments. Front Pharmacol 2017; 8:661. [PMID: 28993732 PMCID: PMC5622197 DOI: 10.3389/fphar.2017.00661] [Citation(s) in RCA: 275] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/05/2017] [Indexed: 12/15/2022] Open
Abstract
Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990's when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine) receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A2A receptor antagonists are promising for the treatment of Parkinson's disease. Clopidogrel, a P2Y12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical SchoolLondon, United Kingdom
- Department of Pharmacology and Therapeutics, The University of Melbourne, MelbourneVIC, Australia
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